hw4/MiniString.java

public class MiniString {
   private String str;
   public MiniString(String str) {
      this.str = str;
   }
   public String makeSubstring(int beginIndex) {
      int length = this.str.length();
      String ret = "";
      for (int i = beginIndex; i < length; i++){
         ret += this.str.charAt(i);
      }
      return ret;
   }
   public String makeSubstring(int beginIndex, int endIndex) {
      int length = this.str.length();
      String ret = "";
      for (int i = beginIndex; i < endIndex; i++){
         ret += this.str.charAt(i);
      }
      return ret;
   }
   public int findIndexOf(char ch) {
      int ret = -1;
      for (int i = 0; i < this.str.length(); i ++ ){
         if (this.str.charAt(i) == ch) {
            ret = i;
            break;
         }
      }
      return ret;
   }
   public int findIndexOf(char ch, int fromIndex) {
      int ret = -1;
      for (int i = fromIndex; i < this.str.length(); i ++ ){
         if (this.str.charAt(i) == ch) {
            ret = i;
            break;
         }
      }
      return ret;
   }
   public int findIndexOf(String str) {
      int ret = -1;
      int sub_length = str.length();
      String cur_str;
      for (int i = 0; i < this.str.length() - sub_length; i++){
         cur_str = this.makeSubstring(i,i + sub_length);
         if (cur_str.equals(str)) {
            ret = i;
            break;
         }
      }
      return ret;
   }  
   public int findIndexOf(String str, int fromIndex) {
      int ret = -1;
      int sub_length = str.length();
      String cur_str;
      for (int i = fromIndex; i < this.str.length() - sub_length; i++){
         cur_str = this.makeSubstring(i,i + sub_length);
         if (cur_str.equals(str)) {
            ret = i;
            break;
         }
      }
      return ret;
   }
}